Dove clock support

On Mon, Jun 18, 2012 at 10:38:41PM +0200, Sebastian Hesselbarh wrote:

On 06/18/2012 12:11 PM, Andrew Lunn wrote:

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But I'd prefer the driver to take care of clks _and_ PHYs.

That would be nice, but we have to remember that the driver is used
for a number of different Marvell SoC and discreet devices. Only a few
have the ability to turn on/off there clocks and PHYs. So you need to
abstract this in such a way it does not break older chipsets.

Well, I'd suggest to find a good name for clk and PHY, e.g.
"pcie.0","clk" and "pcie.0","phy", and let the driver decide if it
enables/disables clk/PHY when it gets a valid struct clk back.

Although struct clk is meant for clocks there is no difference
between clocks and PHYs. Moreover, dove handles PHY control in
it's clock control register sometimes. (Well, it is maybe external
clock to PHY so it's ok)

But first I suggest to have a drivers/clk/clk-orion (which I have
somehow) and I already sent you a proposal some weeks ago.

I wasn't sure how to hook up drivers/clk/clk-orion with the platform
itself but now that there are some other clock drivers available I'll
have another look.

I have the datasheets for dove and kirkwood but with other orion-based
platforms I cannot tell the differences. Maybe someone can comment on
the different other platforms.

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One more: I suggest to clean the clk names of orion platforms,
they are a mess

Do you have a proposal?

Hi Sebastian

Hmm, well if you look at mach-kirkwood/common.c there is:
- orion_spi.0/NULL (underscore)
- orion-ehci.0/NULL (dash)
- pcie/0
- kirkwood-i2s/NULL

First, I suggest to choose either underscore or dash. Second, pcie/0
should be kirkwood-pcie.0/NULL (or orion-pcie.0) and if we consider
having PHY "clocks" it should be kirkwood-pcie.0/clk.

Are you aware these names are not free choice.

The code does:

 hpriv->clk = clk_get(&pdev->dev, NULL);

meaning the name needs to match the name in the platform device
structure. This platform device structure is created in
plat-orion/common.c. The driver also uses this name in its
platform_driver structure. Boards which make use of device tree will
also use this name in the auxdata to translate the DT name.

So, it would be nice to have uniform names, but it is a lot of work.

    Andrew